Downwash airflow field distribution characteristics and their effect on the spray field distribution of the DJI T30 six-rotor plant protection UAV

Spray characteristics are the fundamental factors that affect droplet transportation downward, deposition, and drift. The downwash airflow field of Unmanned Aviation Vehicle (UAV) primarily influences deposition drift by changing spray characteristics. This study focused mainly on effect UAV nozzle position spatial distribution velocity distribution, which two To abovementioned characteristics, computational fluid dynamics based lattice Boltzmann method (LBM) was used to simulate DJI T30 six-rotor plant protection at different rotor rotational speeds (1000-1800 r/min). A particle image velocimetry system (PIV) utilized record with rotors (0-1800 r/min) or positions (0, 0.20 m, 0.35 0.50 m from motor). simulation experimental results showed exhibited ‘dispersion-shrinkage-redispersion’ development rule. In initial dispersion stage airflow, there were obvious high-vorticity low-vorticity regions in field. Moreover, region concentrated below motor, middle area rotors. Additionally, Y-direction fluctuated 0.4-1.2 under rotor. When developed 3.2 rotor, a slight decrease. Above started drastically Therefore, it is recommended should not exceed flight height during spraying operations. caused atomization angle, concentration, width decrease while increasing vortex scale when activated. increase speed promoted trend. installed various radial locations completely different. directly relatively symmetrical. droplets clearly moved toward right induction stronger vortices. resulted higher concentration right-half However, left tip. For four positions, 0 average much higher. slower other positions. motor. research could understanding its influence Meanwhile, provide some theoretical guidance for choice Keywords: protection, UAV, DOI: 10.25165/j.ijabe.20231602.8094 Citation: Zhang H Y, Wen S, Chen C L, Liu Q, Xu T S D, et al. Downwash their UAV. Int J Agric & Biol Eng, 2023; 16(2): 10-22.